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<H1><A NAME="SECTION03730000000000000000"></A><A NAME="seccommonerrors"></A>
<BR>
Common Errors in Calling LAPACK Routines
</H1>

<P>
As a first step, the user should always carefully read the leading
comments of the LAPACK routine.  The leading comments give a detailed
description of all input/output arguments and can be viewed in the source
code, on the LAPACK webpage, or in this users' guide.

<P>
For the benefit of less experienced programmers, we list the most
common programming errors in calling an LAPACK routine.
These errors may cause the LAPACK routine to report a failure,
as described in Section&nbsp;<A HREF="node136.html#secfailures"
 NAME="21092">7.3</A>;
they may cause an error to be reported by the system;
or they may lead to wrong results -- see also
Section&nbsp;<A HREF="node139.html#secwrongresults">7.4</A>.

<P>

<UL><LI>wrong number of arguments

<LI>arguments in the wrong order

<LI>an argument of the wrong type (especially real and complex 
arguments of the wrong precision)

<LI>wrong dimensions for an array argument

<LI>insufficient space in a workspace argument

<LI>failure to assign a value to an input argument

</UL>

<P>
Some modern compilation systems, as well as
software tools such as the portability checker in 
Toolpack&nbsp;[<A
 HREF="node151.html#Toolpack">88</A>], can check that arguments agree in number and type;
and many compilation systems offer run-time detection
of errors such as an array element out-of-bounds or use of an
unassigned variable.

<P>
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<ADDRESS>
<I>Susan Blackford</I>
<BR><I>1999-10-01</I>
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